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WolfX700 Measurement of Audio-GD NFB-6 Preamp/Headphone Amp

WolfX-700

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Recently, as the semester is coming to an end, I am very busy. In any case, the measurement should continue.

I received a device to be measured from a friend. It was a pure analog device from Audio-GD, my impressive manufacturer.

Someone said before that the DAC of Audio-GD I measured cannot represent the technical level of Audio-GD. Because Audio-GD is undoubtedly better at analog circuits than digital circuits.

Well, here comes the pure analog device.

Let's see how it performs!

Photo.jpg


Rear.jpg


The appearance is not good, and what I hate most is the choice of screws-these screws show the quality of this product on one side. You need to know that the use of more "decent" screws does not need to increase the cost-but can improve the appearance of the device.

But I have to say that although the buttons are ugly, the feel of pressing is better than the buttons of Holo Audio.

You can switch the working mode of Preamp and Headphone Amp by pressing keys. The same goes for volume and gain and input.

There are several special interfaces for Audio-GD on the back, but unfortunately I decided to use balanced wiring for measurement.

Okay, the nonsense ends, and the measurement starts:

Measure the Preamp part first:

LineoutLGain-Full-Dash.jpg

:facepalm:

Since the maximum output is less than 4V when the low gain 4V input is used, the 4V input and 4V output under the high gain are measured again (volume setting 48 MAX = 79).

Lineout4V-Dash.jpg

:facepalm::facepalm::facepalm::facepalm::facepalm::facepalm:

DR@Low Gain(Full Vol)
Dynamic-Range---Low-Gain-No-Wt.jpg


DR@High Gain(Full Vol)
Dynamic-Range---High-Gain-No-Wt.jpg


LowGain-Full-THD+N-Ratio.jpg


HighGain-Vol48-THD+N-Ratio.jpg


IMDSMP:
Low-Gain-Full-SMPTE-Ratio.jpg

High-Gain-Vol48-SMPTE-Ratio.jpg


Multitone:
LowGain-Full-Multitone.jpg


HighGain-Vol48-Multitone.jpg


For Preamp, the most important feature is the volume control. Let's take a look at the volume control of this device:

Volume.jpg


SINAD.jpg


The above volume / SINAD chart shows a very interesting feature: as the volume increases, SINAD remains unchanged for a long area ...:facepalm::facepalm:

I carefully studied how this happens: as the volume increases, the noise floor also rises synchronously ... :facepalm::facepalm::facepalm: it's an indescribable feature ...:facepalm::facepalm::facepalm::facepalm::facepalm: :


NoiseLevel.jpg


Although Preamp's measurement results have been bad, in fact this is nothing!

Please stabilize your butt and see the next headphone amplifier section measurement:

50MAXHP.jpg

:facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm:

504VHP.jpg

:facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm:

3004VHP.jpg

:facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm:

OI.jpg



To sum up:
The Audio-GD products I've measured so far are unquestionably crap. Whether it is a product containing digital circuits or a pure analog circuit product.
 

Tks

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De ja vu

I really have a distaste for this company. I've never seen so many confirmations of fake specs than with these guys.

Also one thing I will never understand. How do so many people hype this brand? First off the branding font itself looks childishly bad. Second, the devices (EVERY SINGLE ONE OF THEM I KID YOU NOT) look like DIY projects that use mixed and matched parts. What I mean by this is awfully uninspired design, and just no degree of any serious finishing. There's no complexity to the design where you feel like "damn this company went the extra mile to do things the hard way for some reason"..

Lastly their marketing of course is par for the course.

How companies like this have even an audience is beyond me.

Thank you wolfX and amir for your work getting these on your bench. It's the nonsense of devices like this I really appreciate being demonstrated for what they are.
 
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WolfX-700

WolfX-700

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Wow, normally I’d be interested in power vs distortion into various loads, but with results this poor, I don’t think it’s even necessary!
I measured more data, but I don't think it is necessary to take everyone's time to see them, because the conclusion is clear: this is garbage!
 

NTomokawa

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Man, that 3rd harmonic spike is massive.
Because according to Audio-GD:
We known that the proper 2nd THD makes the sound become smooth and rich, the proper 3rd THD makes the sound become transparency and lively, how to adjust the level of 2nd and 3rd THD is the secret technology of the designers, that is why some audio devices have the higher distortion like phono, and some few very expensive European made audio devices had better musical to most people than some others low distortion devices .
 

AudioJester

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About 10-15 yrs ago I fell for the Audio-GD hype on head-fi forums. I bought one of their "monster" reference dacs and sold it on less than a year later. Never understood the rave reviews, and never missed the thing. It was a crazy time as people were upgrading the dac each time a new revision came along.

Interestingly, now some of the people I still converse with admit they felt obliged to run with the hype even though in retrospect there was no sound revelation. It was all psychological!
 

Svperstar

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About 10-15 yrs ago I fell for the Audio-GD hype on head-fi forums. I bought one of their "monster" reference dacs and sold it on less than a year later. Never understood the rave reviews, and never missed the thing. It was a crazy time as people were upgrading the dac each time a new revision came along.

Interestingly, now some of the people I still converse with admit they felt obliged to run with the hype even though in retrospect there was no sound revelation. It was all psychological!

Reminds me of when NOS DACs in general were hyped as this amazing new thing on Head-Fi. Were ANY of them any good?
 

YSC

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Reminds me of when NOS DACs in general were hyped as this amazing new thing on Head-Fi. Were ANY of them any good?
The holo audio spring and may?

Please stabilize your butt and see the next headphone amplifier section measurement:

View attachment 45360
:facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm:

View attachment 45361
:facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm:

View attachment 45362
:facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm::facepalm:
Ok, I admit I spill my coffee in the office late afternoon. hell man the 44dB SINAD is AMAZING (-ly HOW DARE YOU). but really one side track on this.... shameful brand that I owned their 9018 dac back in 2014... aside from that their reference 9 amp which were subjectively used by a lot of reviewers. while I am pretty sure that is a huge crap (I mean literally huge and heavy, and pollutes the environment by the shear component waste..) are there any chance you will be measuring any of those multi grand monster amps?? You know, always reading about great measurements arn't fun
 

Veri

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skillful engineering (acc. to their convictions trying to achieve something 'sheshul') or just covering up poor engineering with skillful advertising ?

3712858.jpg
And of course "kingwa" in big letters :D
 

YSC

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Tbh this thing considering the harmonics seems like some kind of feature and the noise floor is reasonable (at audio gd standard at least)
 

123456789

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You are missing the real point here....
Why to buy two amplifiers when you can have "two in one". A solid state amplifier, that emulates harmonics from tube amp! :D
 
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